Action Synopsis: Bat Conservation About Actions

Install green bridges as road/railway crossing structures for bats

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms

Study locations

Key messages

  • One study evaluated the effects of installing green bridges as road crossing structures for bats. The study was in the UK.




  • Use (1 study): One study in the UK found that a green bridge was used by 97% of bats crossing a road.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A study in 2014 at one green bridge over a road in the UK (Berthinussen & Altringham 2015) found that the green bridge was used by 97% of bats that crossed the road. A greater number of bats crossed the road using the green bridge (97%, 121 of 125 bats) than crossed the road below at traffic height (2.4%, 3 of 125 bats) or above traffic height (0.8%, 1 of 125 bats). Four bat species were recorded using the green bridge for crossing and foraging: common pipistrelle Pipistrellus pipistrellus (92 bats), soprano pipistrelle Pipistrellus pygmaeus (22 bats), Natterer’s bats Myotis nattereri (2 bats), and a whiskered or Brandt’s bat Myotis mystacinus or Myotis brandtii (1 bat). Four bats using the green bridge could not be identified to species. One common pipistrelle and two unidentified bats were recorded crossing the road below the green bridge at traffic height. One common pipistrelle crossed the road below above traffic height. The green bridge was built over a four-lane road in 2005 to maintain access to a historic property and provide a wildlife crossing. The bridge (50 m long x 30 m wide x 6–8 m high) had a paved road over it with grass verges, shrubs, and trees (2–3 m high) on each side. Observations of crossing bats and recordings of bat calls were made during 10 x 60-minute surveys at dusk or dawn in June–August 2014.

    Study and other actions tested
Please cite as:

Berthinussen, A., Richardson O.C. and Altringham J.D. (2021) Bat Conservation: Global Evidence for the Effects of Interventions. Conservation Evidence Series Synopses. University of Cambridge, Cambridge, UK.


Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Bat Conservation

This Action forms part of the Action Synopsis:

Bat Conservation
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust